# include <bits/stdc++.h>
using namespace std;
const int nmax = 1e6 + 55;
char aux[nmax],s[nmax];
int main(void)
{
    long long d;
    fscanf(fopen("next.in","r"),"%s%lld",aux+1,&d);
    int n=strlen(aux+1);
    long long r=0;
    for (int i=n;i;--i) s[i]=aux[n-i+1]-'0',r=(r*10+s[i])%d;r=(d-r)%d;
    for (int i=1;i<=n || r;++i,r/=10) s[i]=(r+=s[i])%10;
    while (s[n+1]) ++n;
    freopen("next.out","w",stdout);
    for (int i=n;i;--i) printf("%d",int(s[i]));
    return printf("\n"),0;
}